The invention relates to improvements in ultraviolet lamps useful for processing semiconductor substrates and other uses.
For ultraviolet (UV) curing, especially for semiconductor related applications, high deep UV and sub-200 nm radiations are desired. Although there are high power, high pressure Hg bulbs available for UV curing, the high Hg pressure (typically >1000 Torr) provides insufficient emissions below 200 nm. Low pressure Hg and amalgam bulbs have efficient emissions at 254 nm and 185 nm, but the power is too low to be used for applications demanding high deep UV output.
It has been discovered that high power, low pressure (<100 Torr) UV lamps of the type disclosed in U.S. Pat. No. 7,569,791 have short bulb lifetime (typically <100 hours) which makes such UV lamps uneconomical for semiconductor related or other applications. Thus, there is a need for improving bulb's lifetime of high power, low pressure UV lamps for semiconductor related applications or other applications.